Build PyPi packages with submodules enabled

Fixes #195

Author: MarJMue

.github/workflows/python-publish.yml

@@ -9,6 +9,8 @@ jobs:
 
     steps:
     - uses: actions/checkout@v4
+      with:
+        submodules: recursive
     - name: Set up Python
       uses: actions/setup-python@v5
       with: